1. Field of the Invention
The present invention relates to a two-dimensional (2D)/three-dimensional (3D) convertible display using a pinhole array, and more particularly, to a 2D/3D convertible display, which is easily converted between 2D and 3D and vice versa, using an electro-optic material of which the refractive index varies according to applied power. The present application is based on Korean Patent Application No. 2001-55916, filed Sep. 11, 2001, which is incorporated herein by reference.
2. Description of the Related Art
A stereoscopic video display, which displays three-dimensional (3D) video broadly including stereoscopic images and 3D images, is classified on the basis of stereoscopic display method, viewpoint, observation conditions and the condition of whether or not an observer wears supplementary glasses. Binocular parallax is used so that an observer recognizes video that is provided by a display stereoscopically. That is, if video that is observed from various angles is received by both eyes, the observer's brain perceives the video in three dimensions. A display method includes stereoscopic display and volumetric display on the basis of recognition of stereoscopic views from a stereoscopic video display. In the stereoscopic display, two pieces of a 2D image having binocular parallax are divided into images that are taken from the right and left eye, respectively, to allow stereoscopic recognition. Since right and left images that are taken from the two eyes are displayed, there is a disadvantage of stereoscopic views in which they are recognized only from a single viewpoint. In the volumetric display, stereoscopic images in which an object is taken in various directions is displayed. Thus, there is an advantage in obtaining 3D images even in a case where an observing position varies, that is, in a case where the observer observes the object from various directions.
A method for displaying 3D images, which is a technique of displaying 3D images and displays binocular parallax images that are taken in various directions, includes a parallax panoramagram method, a lenticular method, an integral photography or volumetric-graph (IP) method, and a slit scan method.
Among the methods, the IP method does not require additional glasses for observation, and in the IP method, stereoscopic video is automatically obtained in a desired position, and thus the IP method is very useful to create 3D video. A display using the IP method includes a micro lens array or pinhole array and is used in many applications such as medical science, engineering, and simulation.
FIG. 1 illustrates a conventional 3D video system and method for implementing the same. An object 11 is taken by a TV camera 13 through a lens array 12, and a video signal is transmitted to a display 15 using a transmitting and receiving device and is reproduced on the display 15 through a pinhole array 16, thereby implementing 3D video. In the structure, a problem may occur in which the concave and convex images of the object to be implemented are placed in opposite directions, and thus, the system further includes a converter 14 for correcting the concave and convex images in a transmission and reception step. In this case, the pinhole array 16 is formed on the front surface of the conventional display 15 to allow received video to be stereoscopically reproduced. Here, the pinhole array 16 serves as a lens array.
A system for simulation or medical analysis, which requires the 3D video system, also requires 2D video. However, in the conventional 3D display, 2D and 3D video cannot be selectively implemented.